Improved mattress assembly



April 1962 J. E. BELL, JR 3,027,573

IMPROVED MATTRESS ASSEMBLY Filed May 27, 1959 INVENTOR JAMES EDMUNDBELL, JR

BY W

ATTORNEY United States Patent U 3,027,573 IMPROVED MATTRESS ASSEMBLYJames Edmund Bell, Jr., Greenville, Del., assignor to E. I. du Pont deNemours and Company, Wilmington, Del, a corporation of Delaware FiledMay 27, 1959, Ser. No. 816,192 2 Claims. (Cl. 5-355) Bed mattresses varywidely in their properties, construction, and the materials from whichthey are made. In general, they consist of a firm but resilient innermaterial encased in a substantial cloth ticking. Felts of cotton or ofcurled hair have been widely used in the core. Arrangements of coilsprings generally covered with cotton felt are common. More recently,foam pads of elastomeric materials have been used as the resilient corematerial. The assembly of all of these types requires skill andspecialized manufacturing equipment; and, therefore, mattresses arecommonly offered to the public in the form of a complete unitaryarticle. They are large and awkward in shape and too heavy to be handledeasily. Although they are subject to soil from many sources, it isusually impractical to clean them or to make any repairs in them withhome facilities. For cleaning, it is necessary to return the mattress toa specialized service for complete dismantling and reassembly. For thisreason, many kinds of protective coverings have been proposed and are ingeneral use.

The taste of the public also varies widely in the choice of bothaesthetic and working qualities desired. To satisfy this need, manycolors and designs in the covering fabrics are offered and the internalconstruction is varied to give hardness or softness, or any intermediaterange of resilience. This means that many different models must beprovided by the vendor and consequently, large inventories are required.

It is an object of this invention to provide a compound mattress whichcan be easily assembly from its elements. Another object is to provide anew type of mattress with a luxurious, enveloping and cushioningsurface. It is a further object of this invention to provide a mattresshaving the firm supporting qualities of an elastic foam, but with dampedrecovery properties to avoid the quick bounce of such foam mattresses. Astill further object of this invention is to provide a mattressassembled from a relatively small number of different elements toprovide wide variations in color, pattern, hardness, and otherqualities. A further object is to provide a mattress which may be easilydisassembled into its elements for repair and cleaning and in which allof the elements are completely washable and sterilizable. Other objectswill appear hereinafter.

These objects are achieved according to this invention by providing acompound mattress consisting of three primary elements, an upperenvelope, a lower envelope, and a core. Each of these elements isconstructed of materials best suited for its particular function, andthe three are readily assembled without special skill or tools to form aluxurious and highly desirable, as well as durable, sleeping mattress.

The upper envelope comprises a quilted sleeping surface extending overthe entire top surface of the mattress and attached thereto a fabricskirt to provide a portion of the side wall. The quilted surface is abatt of highly resilient crimped fibers of a synthetic, linear organicpolymer quilted between a top sheet and a bottom sheet of fabric alsocomposed of synthetic, linear organic polymeric fibers. The quiltingstitching may be in any design desired, and preferably is at asufiicient spacing so as not to inhibit the fluffiness of the coveringenvelope. The side-wall fabric is preferably the same as that used inthe top surface, although it may have an 3,fi27,573 Patented Apr. 3,1962 inner reinforcement, either of fabric or other stiffening a cut.

The crimped resilient synthetic fibers used in the batt permitlaundering in the quilted condition without substantial loss of bulk andresilience and with little if any change in length and width. Acrylicfibers, such as polyacrylonitrile or copolymers containing at leastacrylonitrile in the polymer, such as the copolymer of methyl acrylate,polyamide fibers, such as nylon, polyester fibers, and cellulose acetatefibers have all been found to give satisfactory behavior. It ispreferred to use poly(ethylene terephthalate) fibers.

The batt, before covering, is preferably surfacebonded by applying abinder material to only the extreme upper surface of the batt to bindthe protruding fiber ends together and prevent the leaking of fibersthrough the fabric covering the mattress. Such bonding is readilyaccomplished by spraying.

FIGURE 1 shows an elevated perspective view of the three components ofthis invention.

FIGURE 2 shows an open view of the top component.

In FIGURE 1, there is shown top covering envelope 1, foamed core 2, andbottom covering envelope 3. Side panels 4 are provided for both the topand bottom envelopes. Zipper tracks 5 and 6 are also provided tointerlock the top and bottom envelopes in the composite assembly shownin FIGURE 2.

A three component mattress of this invention including an elastomericcore and a top and bottom covering envelope, is constructed. Anelastomeric twin-sized mattress core, a slab of foamed polyetherurethane, known under the trademark of NOPCO Foam, 6 inches thick isprovided with a bottom covering envelope of cotton fabric and a topenvelope of 70 denier nylon taffeta. The top envelope is a multi-plyassembly of two 70 denier nylon taffeta sheets covering a batt ofpoly(ethylene terephthalate) fibers (2 ounces per square foot), crimpedin accordance with the teachings of U8. Patent 2,311,174 and having astaple length of 4 inches, the filament denier being 1.75. These twonylon sheets are quilted together to provide a bulky covering envelope.Prior to quilting the top envelope, the batt is sprayed lightly with anacrylic resin binder composition known under the trademark of RhoplexD-lS. To provide additional support for the side panels of bothenvelopes, an 8 ounce cotton backing is provided for the side panels ofthe envelopes.

Sheets 7 and 8 of the top envelope cover a batt of synthetic crimpedfibers 9 having a thin spray 10 of the acrylic resin known under thetrademark Rhoplex 15, to hold the fiber ends in place. These sheets arequilted at 3-4 inch intervals in diamond shapes 11 by threads 12, toprovide a bulky, resilient cover for the foamed core 2.

In order to realize the soft and luxuirous feel of the synthetic fiberbatts, light-weight and relatively smooth fabrics are preferred forcovering. Continuous filament fabrics have been found highly desirablein the top cover. However, spun yarns or textured continuous filamentyarns may be used for all or a portion of the top covering fabric toalter the frictional qualities of the surface as desired. Desirablefabrics for the top cover range in weight from 2 ounces to 4.5 ouncesper square yard. The fabrics used on the inner surface of the batt may,if desired, be lighter than those on the outer surface. Continuousfilament nylon fabrics have been found especially desirable.

The lower envelope is similar in size and general form to the upperenvelope except that the main surface is not quilted, but is made from adurable fabric. If desired, this may be a cotton fabric. A fabric skirtwhich forms the bottom portion of the side wall of the mattress issimilar to the skirt portion of the upper envelope but does not extendas far on the side wall. The fabric used in this lower envelope skirtmay be the same as that used in the upper envelope skirt, or it may bedifferent in color, weight, and design as preferred. The two envelopesare identical in dimensions except for the longer extension of the upperenvelope skirt.

The core of the mattress is preferably a shaped slab of a foamedelastomer which may or may not contain molded depressions or designs tovary its firmness and resilience. Its length and width dimensions aresomewhat larger than those of the upper and lower envelopes so that whenplaced within and between the two envelopes the foam core is slightlycompressed.

In assembly, the foamed elastomer core is placed inside one of theenvelopes, the second envelope is drawn over the other side of the core,and the two envelopes fastened together along the edge of their skirtside wall portion. A connecting enclosure means for the two envelopes isprovided in the form of a zipper fastener connecting the edges of theupper and lower skirts and extending at least around one side and oneend of the mattress. In the preferred embodiment, this zipper closureextends completely around the side wall of the mattress, and is of thetype commonly used in the fronts of jackets and which permits a completeseparation of the two sides and easy reassembly.

The compound mattress described is found to have extremely pleasantenveloping and relaxing qualities. The highly resilient batt of crimpedsynthetic fibers permits easy compression under light loads but infurther compression is restrained by the firmer qualities of theclastomer core. The fiber batt tends to recover from compression moreslowly than does a foamed ela'stdrner -core, and it thereby provides adamping effect and greatly reduces the bounciness which ischaracteristic of foam rubber mattresses and which is consideredobjectionable by many.

The compound mattress is lighter and more easily handled than othermattresses of similar thickness and performance qualities. It may bedisassembled easily by simply unfastening the zipper and removing theupper and lower envelopes. The envelopes may be laundered in anysuitable manner including the use of home laundry machines. In mostcases, the bulk and loftiness of the crimped synthetic fiber batts areimproved by laundering and where this does not occur gentle manipulationof fiufiing by hand restores any loss in bulk. Such action is, ofcourse, impossible with conventional mattresses. The lower envelope maybe washed in a similar manner and the foamed elastomer core may bescrubbed without damage. The three primary elements of the compoundmattress may also be sterilized separately if desired.

The amount of crimped synthetic filaments used in the batt of the upperenvelope varies between about 1 ounce ounce and about 4 ounces persquare foot, about 1.8 to about 3 ounces per square foot beingpreferred. Less than about 1 ounce fails to give the desired dampingeffect while an amount greater than about 4 ounces compacts the fibersso tightly that the covering envelope becomes as resilient as the formedelastome'ri'c core and consequently also fails to provide adequatedamping. The thickness of the foamed elastorner core ranges from 3inches to 6 inches depending on the degree of cushioning desired andeconomic factors.

It is critical that synthetic crimped fibers be utilized to provide thedamping characteristic. Natural fibers have been found unsuitable inthat such fibers have very little resilience as compared with thesynthetic crimped fibers and tend to mat together after use to provide avery undesirable cover. I

Any washable binder composition which holds the fiber ends in place canbe utilized, whether thermoplastic, thermosetting or elastomeric. Amongthese suitable binders, there are included washable synthetic rubberlatex, poly(vinyl chloride), ether resins, and epoxy resins. In therubber latex group, neoprene is preferred for its washability.

The compound features of the mattress of this invention are of greatimportance in providing a wide variety of combinations of hardness orsoftness, and color, design and other aesthetic features withoutmaintaining a largeinventory of entirely complete mattresses. A fewtypes of elastomer foam cores providing differences in hardness may beplaced within envelopes of any chosen design to provide wide choice witha relatively small inventory.

Of great importance also are the outstanding comfort and supportingqualities of compound mattresses of this design and the capacity of eachcomponent to be subjected to washings Without deleterious effects.

The mattress assembly of this invention is highly desirable in that thequilted batting of synthetic crimped fibers is free to moveverticallythus providing e'nveloping cushioning which is not obtainedwith normal quilted structures. For a given Weight of batting, thesynthetic fibers will assume two to three times the thickness whichwould be experienced if natural fibers were used, but when compressedwith normal body weight wouldactuab ly be approximately the samethickness as those battings of natural fibers which insulate withoutproviding cushioning. The batting is preferably quilted with a patternthat leaves a minimum of about nine square inches between stitch lines.Such a batting is free from shifting or lumping during washings. Anatural fiber batting must be stitched with a very close pattern toinhibit in part the movement of the fibers, but still such battings havebeen found to shift and lump during washings.

I claim:

1. An improved separable compound mattress assembly characterized by alow resistance to low magnitude compressional deformations anddisproportionately increased high resistance to higher magnitudecompressional deformations, said assembly comprising a foamed polyetherurethane elastomeric interior core unit of given resili'ence, and alaunderable exterior unit surrounding said core, the said exterior unitcomprising a top portion and a detachable bottom portion connectedtogether, said top portion comprising a quilted layer comprising a topsheet ofsynthetic fabric, a bottom sheet of synthetic fabric, and a battcontained between the sheets and comprised of a. quantity 'of resilientcrimped fibers of a solid synthetic linear organic polymer of ethyleneterephthalate stitched in place between said sheets, said quantity offibers ranging from about one and one-half to three ounces per squarefoot of batt and evenly distributed so that said batt possesses aresilience substantially different from said core and recovers fromcompression more slowly than said resilient core to provide a suitabledamping action to eliminate oscillatory vibration effects, or bouncing,in said mattress assembly when the mattress assembly is subjected tocompression loads in use.

2. The improved assembly of claim 1 in which the upper surface of thebatt is coated with a binder material to secure the fibers of the battin position.

References Cited in the file of this patent UNITED STATES PATENTS

1. AN IMPROVED SEPARABLE COMPOUND MATTRESS ASSEMBLY CHARACTERIZED BY ALOW RESISTANCE TO LOW MAGNITUDE COMPRESSIONAL DEFORMATIONS ANDDISPROPORTIONATELY INCREASED HIGH RESISTANCE TO HIGHER MAGNITUDECOMPRESSIONAL DEFORMATIONS, SAID ASSEMBLY COMPRISING A FOAMED POLYETHERURETHANE ELASTOMERIO INTERIOR CORE UNIT OF GIVEN RESILIENCE, AND ALAUNDERABLE EXTERIOR UNIT SURROUNDING SAID CORE, THE SAID EXTERIOR UNITCOMPRISING A TOP PORTION AND A DETACHABLE BOTTOM PORTION CONNECTEDTOGETHER, SAID TOP PORTION COMPRISING A QUILTED LAYER COMPRISING A TOPSHEET OF SYNTHETIC FABRIC, A BOTTOM SHEET OF SYNTHETIC FABRIC, AND ABATT CONTAINED BETWEEN THE SHEETS AND COMPRISED OF A QUANTITY OFRESILIENT CRIMPED FIBERS OF A SOLID SYNTHETIC LINEAR ORGANIC POLYMER OFETHYLENE TEREPHTHALATE STITCHED IN PLACE BETWEEN SAID SHEETS, SAIDQUANTITY OF FIBERS RANGING FROM ABOUT ONE AND ONE-HALF TO THREE OUNCESPER SQUARE FOOT OF BATT AND EVENLY DISTRIBUTED SO THAT SAID BATTPOSSESSES A RESILIENCE SUBSTANTIALLY DIFFERENT FROM SAID CORE ANDRECOVERS FROM COMPRESSION MORE SLOWLY THAN SAID RESILIENT CORE TOPROVIDE A SUITABLE DAMPING ACTION TO ELIMINATE OSCILLATORY VIBRATIONEFFECTS, OR BOUNCING, IN SAID MATTRESS ASSEMBLY WHEN THE MATTRESSASSEMBLY IS SUBJECTED TO COMPRESSION LOADS IN USE.